Revert "drm/virtio: drop prime import/export callbacks"

This patch does more harm than good, as it breaks both Xwayland and
gnome-shell with X11.

Xwayland requires DRI3 & DRI3 requires PRIME.

X11 crash for obscure double-free reason which are hard to debug
(starting X11 by hand doesn't trigger the crash).

I don't see an apparent problem implementing those stub prime
functions, they may return an error at run-time, and it seems to be
handled fine by GNOME at least.

This reverts commit b318e3ff7ca065d6b107e424c85a63d7a6798a69.
[airlied:
This broke userspace for virtio-gpus, and regressed things from DRI3 to DRI2.

This brings back the original problem, but it's better than regressions.]

Fixes: b318e3ff7ca065d6b107e424c85a63d7a6798a ("drm/virtio: drop prime import/export callbacks")
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c
index c59ec34c80a5..eb51a78e1199 100644
--- a/drivers/gpu/drm/virtio/virtgpu_prime.c
+++ b/drivers/gpu/drm/virtio/virtgpu_prime.c
@@ -39,6 +39,18 @@ void virtgpu_gem_prime_unpin(struct drm_gem_object *obj)
 	WARN_ONCE(1, "not implemented");
 }
 
+struct sg_table *virtgpu_gem_prime_get_sg_table(struct drm_gem_object *obj)
+{
+	return ERR_PTR(-ENODEV);
+}
+
+struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
+	struct drm_device *dev, struct dma_buf_attachment *attach,
+	struct sg_table *table)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 void *virtgpu_gem_prime_vmap(struct drm_gem_object *obj)
 {
 	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);